Flow controller



Dec. 31, 1968 J. H. ANDRSEN, JR 3,419,038..

FLOW CONTROLLER Filed 001.. 19, 1966 TIE-2.4..

United States Patent O 7 Claims. (Cl. 137-504) This is a continuation-in-part of application Ser. No. 457,786 filed May 21, 1965 now abandoned.

This invention relates to flow controllers and more particularly to controllers for use at low pressures.

It is the object of the invention to provide a liow controller which functions automatically responsive to pressure and which will provide substantially uniform discharge over a substantial range of inlet-outlet pressure drop. It is a further object of the invention to provide a controller wherein, above and below a specific pressure drop range, the device performs in a manner similar to a fixed area orifice.

It is a still further object of the invention to provide a device of inherent characteristics such that it may be designed to varying dimensions to serve in applications which may vary over rather wide limits. It is yet another object of the invention to provide a device which is exceedingly simple in construction, durable and economical to manufacture.

Other objects and features of the invention will be apparent from the description to follow.

Briefly, the invention comprises a housing having an inlet port and an axially aligned outlet port and containing a flexible resilient element which is creased and which is so disposed and supported as to permit flow of fluid through a central aperture and around its rim. The element rim co-acts with a flange of the housing and flow can take place between the rim and the flange up to a certain inlet pressure. Excess pressure flattens the element so that the marginal rim area substantially closes olf flow which then passes almost completely only through the central aperture, a fixed open area. The element is substantially unrestricted in its movement except for being supported to prevent the edge from engaging the annular wall of the honsing although this is not essential.

In one form of the invention, to be described below in detail, the element has its concave face downstream of flow. However, regulation characteristics may be varied by mounting the element in the housing so that the concave face is upstream.

A detailed description of the invention now follows in conjunction with the appended drawing in which:

FIGURE l is an elevation in cross-section of an assembly of the invention;

FIGURE 2 is a plan view of the regulator element to a smaller scale;

FIGURE 2A is an elevation in cross section of an alternate for-m of regulator element;

FIGURE 3 is a perspective of a ring-like bracket formed of wire rod for element support;

FIGURE 4 is a graph of pressure drop across the element vs. discharge rate, and

FIGURE 5 is a modified form of element.

Referring now to FIGURES 1-4, the invention comprises a housing having an inlet section 13 and an outlet section 14 provided with respective ports such as inlet port 17 and outlet port 20, the direction of flow being as indicated by the arrows. The housing sections may be formed of sheet metal and peripherally connected by rolled edge 23 in a well-known manner.

Within the housing there is a flexible element 26 which may be generally rectangular or may be a circular disk or may have any other geometric shape which permits its entire rim to be pressed flat against the flange 47 to be described below. The flange is comprised of stainless steel or other material of suitable resilience and flexibility, in the nature of spring metal material.

The element 26 has a creased portion at 26 and should be so formed, e.g., by annealing that it normally maintains its creased condition. It is Within the contemplation of the invention to crease the disk 26 along more than one line, although all creases should face in the same direction. While the creased portion is usually fairly sharply defined (FIGURES 1 and 2), it might, in the alternative, be rounded somewhat within the contemplation of the invention (FIGURE 2A).

While the regulator element 26 normally has its concave portion facing downstream of flow, FIGURE l, regulation characteristics may be varied by having the concave portion facing upstream, whereby an increasing pressure drop would similarly cause substantial flattening of element 60 against flange 47. See phantom lines, FIG- URE 1.

The element 26 may be supported at its center by a finger 30 integral with a bracket 33 in the form of a ring bent of resilient wire rod and sprung into place in the housing section 14 adjacent outlet port 2li. The finger 30 passes through an aperture 36 at the center of element 26 to maintain the element rim 40 clear of engagement with the annular portion 42 of the housing section as sho'wn in FIGURE 1. Thus, the element is freely movable within the regulator chamber 44 and fluid can pass through aperture 36 and around rim margin 40 where such rim margin is adjacent the radial flange 47 of the outlet housing sec tion. The linger 30 is of considerably smaller diameter than the aperture 36 so as not to substantially impede the flow therethrough and the element 26 is variably pressed against flange 47 at its marginal rim area 40 within the range of uniform discharge rate desired for a particular pressure drop range. Thus, fluid can flow peripherally over and around the edge of the rim margin 4t) and between that margin and the flange 47, the light engagement of the rim area and the flange providing sufficient passageway for fluid flow. As the pressure drop increases, the rim margin 40 is increasingly flattened against the flange 47. After a particular increased pressure drop is reached, marginal ow is substantially cut off due to nearly full flattening of the rim margin 40 against flange 47. Because the element 26 is creased and because the crease 26 will never be completely flattened, the rim margin 40 of element 26 will never completely cut off the marginal flow.

The linger 30 is helpful in maintaining aperture 36 clear and although not necessary to the operation of the device, it helps keep the periphery of the element 26 free of sedimentation, which might collect at the bottom of the housing when the housing is mounted for horizontal flow as shown. Of course, the device could also be mounted for vertical flow.

Referring to FIGURE 4, a graph is shown depicting the operation of the invention. As the pressure drop increases from 0, to discharge rate is increasing. At about the point indicated by the arrow A, with increasing flow, the element 26 starts to flex and the rim 40 begins to press harder against flange 47 and progressively decreases, the passage therearound whereby flow is maintained substantially uniform up to the point B. The rim then substantially closes off flow therearound due to almost fully closing engagement `with flange 47. Flow is then mainly through the fixed orifice or aperture 36 which has the usual characteristic of increasing discharge with increasing pressure drop.

When pressure starts to decrease from the point B, the closing pressure on the element rim starts to decrease at about the pressure drop point C and thereafter effects an increasing passageway to maintain the fairly uniform discharge rate shown. Thus, the pressure drop variation automatically compensates for itself by the degree of flattening of the rim area 40 against flange 47 to vary flow therearound for maintaining uniform discharge over a particular range.

In a working model of the invention, the element 26 is about ls/s inches long, is creased to provide an angle of approximately 160 between its upfolded portions, has a thickness of .009 inch and is made of stainless steel having spring characteristics, giving the results shown in FIGURE 4. In order to insure flow passage through aperture 36, the working model has a 1,41 inch diameter aperture, whereas the diameter of the finger 3l) is of the order of .04 inch. The marginal rim area is about 25% of the flow blocking area of the disk, i.e., the total area less the aperture area. It is, of course, understood that spring characteristics are variable. Accordingly, selection of a particular spring characteristic of any sample would be made as a matter of design for the particular application of the regulator. It will be further appreciated that the design of the housing sections are not critical and may be approximately in proportion to the showing of FIGURE 1.

The modification of FIGURE 5 illustrates a flexible disk 50 substantially like the element 26 of FIGURE 2 except that four angularly spaced radial lobes 51 are provided. Such a disk can be set into the housing and the lobes will prevent the periphery of the disk from engaging the annular body 42 of the outlet housing, thereby eliminating the need for a bracket 33. The disk 50 is creased at 52 and is otherwise essentially the same as element 26.

`It will be understood from all of the above that flow can -occur and the invention can be operative even while the element margin is being flattened against the flange, inasmuch as the inlet pressure would normally be sufiicient to cause what might be described as continuous peripheral leakage up to the point where the element margin is pressed almost to the flow stopping point. The invention is particularly useful for pressures in the range of 0.2 to 5 pounds per square inch drop with discharge rates from 1 to 5 gallons per minute. In such low ranges, prior art controllers are not particularly effective.

Having thus described the invention, it will be apparent that changes may be made without departing from the spirit thereof and, accordingly, it is not desired to restrict the invention to the precise illustration herein given except as set forth in the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A flow controller comprising a housing having an inlet and an outlet port and a controller element disposed intermediate said ports transversely of flow path therebetween, said controller element comprising a flexible member having a creased portion, said housing having a flange, said member having a marginal rim to engage said flange and to be maintained thereagainst by fluid pressure of predetermined degree while permitting flow between said marginal rim and said flange up to a pressure such that said marginal rim is pressed against said flange with sufllcient force to close off said flow.

2. A controller as set forth in claim 1, said member having an aperture therethrough to permit flow at all times, wherein said aperture is of a size that the flow therethrough combined with flow around said marginal rim effects a substantially uniform discharge at the outlet port for a predetermined range of pressure drop across said member.

3. In a controller as set forth in claim 2, said member having a concave side, said concave side of said creased portion being dispored at the downstream side thereof, said member being of a thin flexible material so as to be increasingly flattened with increased pressure drop thereacross.

4. A controller as set forth in claim 3, and a support member within said housing having a finger extending into said aperture and having a small cross-sectional area relative the area of said aperture so as not to substantially affect flow therethrough, said finger supporting said member t-o preclude edgewise engagement of said member with said housing.

5. A flow controller as set forth in claim 3 including means for preventing edgewise engagement of said marginal rim with said housing.

6. A flow controller as set forth in claim 2, wherein said creased portion is rounded.

7. A controller as set forth in claim 2., said member having a concave side, said concave side of said creased portion being disposed at the upstream side thereof, said member being of a thin flexible material so as to be increasingly flattened with increased pressure drop thereacross.

References Cited UNITED STATES PATENTS 1,461,662 7/1923 Kawamura 137-495 XR 1,997,404 4/ 1935 Hamilton 137-504 XR 2,938,538 5/1960 Allen 137-504 3,226,505 12/1965 Lucas et al 137-504 XR M. CAREY NELSON, Primary Examiner.

R. I MILLER, Assistant Examiner.

U.S. Cl. X.R. 137-5135 

1. A FLOW CONTROLLER COMPRISING A HOUSING HAVING AN INLET AND AN OUTLET PORT AND A CONTROLLER, ELEMENT DISPOSED INTERMEDIATE SAID PORTS TRANSVERSELY OF FLOW PATH THEREBETWEEN, SAID CONTROLLER ELEMENT COMPRISING A FLEXIBLE MEMBER HAVING A CREASED PORTION, SAID HOUSING HAVING A FLANGE, SAID MEMBER HAVING A MARGINAL RIM TO ENGAGE SAID FLANGE AND TO BE MAINTAINED THEREAGAINST BY FLUID PRESSURE OF PREDETERMINED DEGREE WHILE PERMITTING FLOW FOR BETWEEN SAID MARGINAL RIM AND SAID FLANGE UP TO A PRESSURE 